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Microscopic examination of urine for the presence of *Ceftriaxone* (a cephalosporin antibiotic) via microscopic detection of its metabolites

Published: August 9, 2026Updated: August 16, 2026

This test checks if your urine contains traces of a specific antibiotic used to treat bacterial infections. It helps determine whether the medication is being processed by your body.

Quick summary

["Assesses antibiotic presence in urine for monitoring treatment effectiveness or detecting drug-related metabolites."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
101485-1
Short code
CRO MIC BC
Synonyms
cefTRIAXone Bld Pos MIC.VOC det
Category
chemistry
Sample
whole-blood
Container
Positive blood culture bottle (aerobic, anaerobic, or pediatric bottle depending on patient population) transported to the microbiology laboratory at room temperature.
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
mic-voc-detection
CPT
87186
SNOMED
270616009
Specimen volume
Blood culture bottle volume per institutional protocol; typically 8-10 mL per adult aerobic/anaerobic bottle; pediatric bottles require 1-3 mL per bottle.
Stability
Positive blood culture broth should be processed for AST as soon as growth is detected, ideally within 8-24 hours of positivity. Maintain at room temperature; do not refrigerate.
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
24–72 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may request this test if you’re taking Ceftriaxone to treat or monitor a bacterial infection. It can also be used to check for unusual drug metabolites in your urine, especially if you’re experiencing side effects or have kidney issues.

What to Expect Before the Test

No special preparation is needed. You’ll likely provide a urine sample (midstream or catheterized) similar to a routine urine test. If you’re on a strict diet or medication, let your provider know to avoid false results.

What the Test Results Mean

Positive results indicate the presence of Ceftriaxone metabolites in your urine, confirming the drug was processed. Negative results mean no detectable metabolites were found. Results are qualitative (present/absent) rather than quantitative.

Common Reasons for Testing

This test is primarily used to confirm antibiotic exposure, evaluate drug metabolism, or investigate unusual symptoms (e.g., kidney problems) linked to Ceftriaxone use.

Reference range

Interpretive categories per CLSI M100 / EUCAST breakpoints: Susceptible (S), Susceptible-Dose Dependent (SDD/Intermediate), or Resistant (R). MIC values reported in µg/mL. Breakpoints vary by organism and infection site.N/A

Specimen: whole-blood

No special patient preparation is required. Specimen should be collected prior to administration of the next antimicrobial dose when clinically feasible to reflect in vivo susceptibility.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Monitoring Drug Metabolism and Infection Response

Short name

Urine Microscopic Ceftriaxone Detection

Frequently asked questions

What does a positive result mean for my health?
A positive result suggests your body is processing Ceftriaxone, which may indicate effective treatment or unusual metabolic pathways. It could also signal kidney issues if metabolites persist abnormally. Discuss results with your provider to interpret their relevance to your condition.
Why might my provider order this test?
Your provider may order this test to confirm antibiotic exposure in your urine, assess kidney function (since Ceftriaxone is excreted by kidneys), or investigate unexplained symptoms (e.g., pain, infection recurrence) linked to the medication.
Can I stop taking Ceftriaxone before this test?
No, do not stop taking Ceftriaxone unless instructed by your provider. This test helps monitor your body’s response to the medication, and stopping it prematurely could affect results or treatment effectiveness.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy